1. Field of the Invention
The present invention broadly relates to computer system configurations and housings, and more particularly to a computer system cooling configuration.
2. Description of the Related Art
Modern computer systems generally include a housing or an enclosure, a display device and an external command/data input device. The display device may be a CRT (cathode ray tube) monitor, e.g., in a desktop computer system, or it could be a TFT (thin film transistor) screen, e.g., in a portable laptop computer. The external input device may be a keyboard, a pointing device, e.g., a mouse, or a combination of them. The system housing is an enclosure that houses the hardware components that perform, along with necessary software, various processing tasks as requested by the user. The housing may also include one or more power supplies to supply proper electrical power to various electronic hardware circuit elements. Auxiliary storage device drives, e.g., a floppy disk drive or a CD-ROM drive may also be housed within the computer system housing. Additionally, hard disk drive for large amount of data storage is almost invariably included within the computer housing for greater digital information storage capacity.
Electronic components or hardware circuit elements include semiconductor devices. During operation, such electronic components dissipate electrical power (i.e., transform electrical energy into heat energy). At the same time, several key operating parameters of semiconductor electronic devices typically vary with temperature, and reliable device operation within specifications occurs only within a defined operating temperature range. For example, specified performance of a processor is typically achieved only when the temperature of the processing device or "processor", e.g., one or more microprocessors, is maintained below a specified maximum operating temperature. Operation of the processor at a temperature above the maximum operating temperature may result in irreversible damage to the processor. In addition, it has been established that the reliabilities of semiconductor electronic devices decrease with increasing operating temperature.
The heat energy produced by electronic components during operation must thus be removed to a surrounding ambient at a rate which ensures that operational and reliability requirements are met. As component speeds, capabilities and density increase, so does the amount of electrical power dissipated by the components during operation. Cooling mechanisms employed by computer systems must thus allow for more guided airflow into the housing for faster heat transfer from the computer system enclosure to the surrounding ambient.
Today, a typical computer system includes various openings or vents on one or more of the side panels for the housing and/or sometimes on the front bezel itself. The front bezel generally includes power and reset buttons for the system and typically includes areas to allow a user to load CDs and/or floppy disks into corresponding disk drives. The various openings or vents, in conjunction with one or more fans mounted on a metal chassis or included within an appropriate hardware unit, e.g., the power supply unit, allow ambient air to flow into the computer system housing and over the electronic hardware components within the housing, absorbing heat energy from the components before being expelled through the openings or vents in the rear of the metal chassis.
In some computer systems, an independent fan is attached to a heat sink mounted to the processor. However, as the number of processors within the system increases, additional fans or cooling mechanisms are needed to efficiently expel the heat generated by these processors. Fans are rotating electromechanical devices which produce acoustic noise and fail relatively often (i.e., have relatively short operating life). When a fan fails, the components that rely on the cooling air provided by the fan can, and often do, fail as well. Further, fans are relatively heavier in weight, and increasing the number of fans may increase the weight of the computer system housing. Therefore, a computer system housing where adequate component cooling is achieved without undue multiplicity of cooling fans may be desirable.
The power supply unit normally produces more heat energy than most of the other electronic components. It may also be desirable to have a computer system chassis that keeps the power supply unit and its cooling system physically separated from the rest of the system hardware mounted on the chassis so as to reduce heat dissipation around the rest of the system hardware.
The enclosure for computer system components has a limited volume. The expandability of system processing power or system storage capacity, e.g., on-board caches and RAMs (Random Access Memory), depends, among other factors, on the size or volume of the computer system housing. Further, increase in the number of electronic components that are housed within the enclosure may necessitate proportionate availability of adequate cooling means for reliable operation of the computer system. Therefore, it may be desirable to optimize the component packing density within the housing while maintaining proper airflow through the computer system components for adequate cooling.